1. Field of the Invention
This invention relates to a method for manufacturing a battery in which a solid electrolyte layer is interposed between active material layers, a battery manufactured by this method, and a vehicle and an electronic device including this battery.
2. Description of the Related Art
Conventionally, as a method for producing a chemical battery such as a lithium-ion secondary battery, a technology for laminating metal foils as current collectors having respectively positive-electrode or negative-electrode active materials attached thereto with a separator disposed therebetween and impregnating the separator with an electrolytic solution has been known. However, a battery including a highly volatile organic solvent as an electrolytic solution needs to be carefully handled. Further, for required further miniaturization and higher output, a technology for producing an all-solid-state battery by microfabrication using a solid electrolyte in place of an electrolytic solution has been and is being proposed in recent years.
For example, JP2005-116248A (hereinafter, referred to as “patent literature 1”) discloses a technology for forming an active material layer having an uneven surface on a metal foil, which will become a current collector, by an ink-jet method and successively three-dimensionally laminating a solid electrolyte layer and another active material layer by the ink-jet method so as to flatten the unevenness. In this technology, the above space structure is obtained by laminating a multitude of layers mixedly including different functional layers such as the positive and negative active material layers and the solid electrolyte layer formed by one printing process by recoating. At this time, every time one layer is applied, a drying treatment is performed to volatilize a solvent contained in ink.
To obtain good electrochemical properties in a battery in which an electrolyte layer is interposed between positive and negative active material layers, it is important that the active material layers and the electrolyte layer closely contact with each other at interfaces between them. In the case of a liquid electrolyte, the electrolyte penetrates into recessed portions of fine unevenness on active material layer surfaces. However, particularly in the case of a solid electrolyte, the active material layers and the electrolyte layer need to closely contact with each other at the interfaces between them. However, no consideration is made on this in the above prior art and there has been room for improvement in obtaining a battery having good electrochemical properties.